Variable spray angle injector arrangement

ABSTRACT

An injector, comprising, an injector body comprising, an inner wall that defines an injector cavity for fluid, at least one inlet channel into the injector cavity, and at least one outlet channel from the injector cavity, a plunger that defines at least one passageway between the injector cavity and the at least one outlet channel, the plunger being movable longitudinally in the injector cavity between at least: a first open arrangement in which the at least one passageway is positioned to direct fluid into the at least one outlet channel at a first position, and a second open arrangement in which the at least one passageway is positioned to direct fluid into the at least one outlet channel at a second position different from the first position.

FIELD OF THE DISCLOSURE

The present disclosure relates to an injector for spraying fluid invarious systems of internal combustion engines. More particularly, thepresent disclosure relates to injector having variable spray angles, andto methods for using the same.

BACKGROUND OF THE DISCLOSURE

Internal combustion engines typically include various systems, forexample, combustion system, exhaust system, which may require aninjector for spraying fluid. Combustion systems typically use injectorsto spray fuel into combustion chambers of internal combustion enginesand exhaust systems typically use injector to spray diesel exhaust fluidinto decomposition reactor. Improved combustion systems, and exhaustsystems are consistently required to meet the ever-increasinggovernmental and regulatory demands for emissions abatement (e.g.,nitrogen oxides (NO_(x)), particulate matter (PM), and hydrocarbons(HC)) and increased fuel economy. One technique for improving combustionsystems involves controlling the mixing of fuel sprays with air incombustion chambers based on engine load and engine speed, for example.

SUMMARY

According to an embodiment of the present disclosure, an injector bodycomprising:, an inner wall that defines an injector cavity for fluid, atleast one inlet channel into the injector cavity, and at least oneoutlet channel from the injector cavity, a plunger that defines at leastone passageway between the injector cavity and the at least one outletchannel, the plunger being movable longitudinally in the injector cavitybetween at least: a first open arrangement in which the at least onepassageway is positioned to direct fluid into the at least one outletchannel at a first position, and a second open arrangement in which theat least one passageway is positioned to direct fluid into the at leastone outlet channel at a second position different from the firstposition. According to one aspect of this embodiment, the first positionis spaced longitudinally from the second position. According to anotheraspect of this embodiment, the at least one outlet channel has an inletend, an outlet end, and a channel axis between the inlet end and theoutlet end, and wherein the first position is located on a first side ofthe channel axis and the second position is located on a second side ofthe channel axis. In yet another aspect of this embodiment, the plungeris further movable to a closed arrangement in which the at least onepassageway is prevented from directing fluid into the at least oneoutlet channel. According to yet another aspect of this embodiment, theinner wall of the injector body blocks the at least one passageway whenthe plunger is moved to the closed arrangement. In another aspect ofthis embodiment, the plunger is further movable to a third openarrangement in which the at least one passageway is positioned to directfluid into the at least one outlet channel at a third position locatedlongitudinally between the first and second positions. In yet anotheraspect of this embodiment, the at least one passageway is narrower thanthe at least one outlet channel.

In another embodiment of the present disclosure, the method comprising,positioning a plunger in a first open arrangement in a body having anoutlet channel, directing fluid through the plunger in the first openarrangement and into a first side of the outlet channel to produce afirst spray trajectory from the outlet channel, moving the plunger to asecond open arrangement, and directing fluid through the plunger in thesecond open arrangement and into a second side of the outlet channel toproduce a second spray trajectory from the outlet channel different fromthe first spray trajectory. Another aspect of this embodiment, with theplunger in the first open arrangement, the fluid has a first velocitydistribution in the outlet channel, and with the plunger in the secondopen arrangement, the fluid has a second velocity distribution in theoutlet channel different from the first velocity distribution. In yetanother aspect of this embodiment, the first velocity distribution isbiased toward the first side of the outlet channel and the secondvelocity distribution is biased toward the second side of the outletchannel. In another aspect of this embodiment, the outlet channel has achannel axis, the first spray trajectory having a first spray anglerelative to a reference plane that is deeper than an angle between thechannel axis and the reference plane, and the second spray trajectoryhaving a second spray angle that is shallower than the channel axis.According to yet another aspect of this embodiment, the moving step isperformed based on at least one engine operating condition. In anotheraspect of this embodiment, moving the plunger to a third openarrangement, and directing fluid through the plunger in the third openarrangement and into the outlet channel to produce a third spraytrajectory from the outlet channel, wherein moving the plunger to thethird open arrangement is performed based on at least one engineoperating condition. According to another aspect of this embodiment,with the plunger in the third open arrangement, the fluid has a thirdvelocity distribution in the outlet channel. Another to yet anotheraspect of this embodiment, the third velocity distribution is balancedbetween the first side and the second side of the outlet channel. In yetanother aspect of this embodiment, the third spray trajectory has athird spray angle that follows the channel axis.

In yet another embodiment of the present disclosure, a combustion systemcomprising, a combustion chamber, a piston disposed in the combustionchamber, a injector having an injector body, the injector bodycomprising an inner wall that defines an injector cavity, at least oneinlet channel into the injector cavity, and at least one outlet channelfrom the injector cavity, a plunger that defines at least one passagewaybetween the injector cavity and the at least one outlet channel, theplunger being movable in the injector cavity between at least: a firstopen arrangement in which the at least one passageway is positioned todirect fluid into the at least one outlet channel at a first position,and a second open arrangement in which the at least one passageway ispositioned to direct fluid into the at least one outlet channel at asecond position different from the first position. According to anotheraspect of this embodiment, the first position is spaced longitudinallyrelative to a direction of movement of the plunger from the secondposition. According to yet another aspect of this embodiment, the atleast one outlet channel has an inlet end, an outlet end, and a channelaxis between the inlet end and the outlet end, and wherein the firstposition is located on a first side of the channel axis and the secondposition is located on a second side of the channel axis. In yet anotheraspect of this embodiment, the at least one passageway is narrower thanthe at least one outlet channel.

According to another embodiment of the present disclosure, an exhaustsystem, comprising a particulate filter, a decomposition reactordownstream of the particulate filter, a selective catalytic reductionsystem downstream of the decomposition reactor, and an injector havingan injector body, the injector body comprising, an inner wall thatdefines an injector cavity, at least one inlet channel into the injectorcavity and at least one outlet channel from the injector cavity, aplunger that defines at least one passageway between the injector cavityand the at least one outlet channel, the plunger being movable in theinjector cavity between at least: a first open arrangement in which theat least one passageway is positioned to direct fluid into the at leastone outlet channel at a first position, and a second open arrangement inwhich the at least one passageway is positioned to direct fluid into theat least one outlet channel at a second position different from thefirst position, wherein the injector is disposed in the decompositionreactor. According to one aspect of this embodiment, the first positionis spaced longitudinally relative to a direction of movement of theplunger from the second position. According to another aspect of thisembodiment, the at least one outlet channel has an inlet end, an outletend, and a channel axis between the inlet end and the outlet end, andwherein the first position is located on a first side of the channelaxis and the second position is located on a second side of the channelaxis. According to yet another aspect of this embodiment, the at leastone passageway is narrower than the at least one outlet channel.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of thisdisclosure, and the manner of attaining them, will become more apparentand the invention itself will be better understood by reference to thefollowing description of embodiments of the invention taken inconjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic cross-sectional view of an exemplary injector ofthe present disclosure having an injector body with a plurality ofoutlet channels and a plunger with a plurality of passageways, theplunger shown in a closed arrangement;

FIG. 2 is another schematic cross-sectional view of the injector of FIG.1 shown with the plunger in a first open arrangement;

FIG. 3 is yet another schematic cross-sectional view of the injector ofFIG. 1 shown with the plunger in a second open arrangement;

FIG. 4 is yet another schematic cross-sectional view of the injector ofFIG. 1 shown with the plunger in a third open arrangement;

FIG. 5 is a detailed view of the circled portion of the injector of FIG.4;

FIGS. 6A-6C are cross-sectional views of various outlet channels;

FIG. 7 shows a first schematic fluid trajectory corresponding to thefirst open arrangement of FIG. 2;

FIG. 8 shows a first schematic velocity distribution for the fluid ofFIG. 7;

FIG. 9 shows a second schematic fluid trajectory corresponding to thesecond open arrangement of FIG. 3;

FIG. 10 shows a second schematic velocity distribution for the fluid ofFIG. 9;

FIG. 11 shows a third schematic fluid trajectory corresponding to thethird open arrangement of FIG. 4;

FIG. 12 shows a third schematic velocity distribution for the fluid ofFIG. 11; and

FIG. 13 is a schematic view of the injector spraying the first, second,and third fuel trajectories of FIGS. 7, 9, and 11 into a combustionchamber;

FIG. 14 is a schematic view showing an exhaust system with the injectorof FIG. 1.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate exemplary embodiments of the invention and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

Referring initially to FIG. 1, an injector 10 is illustratedschematically. The injector is configured to inject fuel into acombustion chamber 1308 (FIG. 13) of an internal combustion engine (notshown) or diesel exhaust fluid into decomposition reactor of an exhaustsystem of an internal combustion system (not shown). Injector 10 hasfirst end 12, a second end 14, and a longitudinal axis A. First end 12of injector 10 may be an upper end that is spaced outwardly relative tothe combustion chamber 1308, and second end 14 of injector 10 may be alower end that is spaced inwardly relative to combustion chamber 1308.

The illustrative injector 10 includes an elongate injector body 20.Although injector body 20 is shown as a unitary construct in FIG. 1,injector body 20 may be constructed of a plurality of individual piecesassembled together. Injector body 20 includes an inner wall 21 thatdefines an injector cavity 22 to receive fluid. Near the first or upperend 12, injector 10 includes at least one inlet channel 24 for receivingfluid from a fluid supply circuit or rail (not shown) and directing thefluid into injector cavity 22. Near the second or lower end 14, injector10 includes a sac 26 with at least one outlet channel 28, illustrativelya plurality of radially-spaced outlet channels 28, for delivering fluidfrom injector cavity 22 to combustion chamber 1308 (FIG. 13).

The illustrative injector 10 also includes a plunger 30 in injectorcavity 22. Plunger 30 may also be referred to herein as a needle ornozzle valve, for example. The illustrative plunger 30 includes a head32 arranged toward first end 12 of injector 10, a tip 34 arranged towardsecond end 14 of injector 10, and a shaft 36 extending therebetween. Tip34 of plunger 30 defines at least one passageway 38, illustratively aplurality of radially-spaced passageways 38, arranged in fluidcommunication with injector cavity 22.

Plunger 30 may be configured for reciprocal and longitudinal movement ininjector cavity 22 between at least one closed arrangement and aplurality of open arrangements. Plunger 30 is shown in a closedarrangement in FIG. 1. In this closed arrangement, passageways 38 do notcommunicate with outlet channels 28. Instead, passageways 38 interfacewith inner wall 21 of injector body 20, which prevents fluid in injectorcavity 22 from reaching outlet channels 28 via passageways 38. Plunger30 may be biased in this closed arrangement, such as using a spring (notshown). Plunger 30 is shown in three different open arrangements inFIGS. 2-4. In each open arrangement, tip 34 of plunger 30 is movedlongitudinally relative to the closed arrangement to place passageways38 in fluid communication with outlet channels 28, which allows fluid ininjector cavity 22 to reach outlet channels 28 via passageways 38. Theseopen arrangements are described further below.

The illustrative injector 10 further includes an actuating system 40operably coupled to plunger 30 to control movement of plunger 30 ininjector cavity 22 between the open and closed arrangements. Actuatingsystem 40 may control movement of plunger 30 based on one or more engineoperating conditions (e.g., engine load, engine speed). Actuating system40 may include a solenoid actuator, a piezoelectric actuator, amagnetostrictive actuator, or another suitable actuator for controllingmovement of plunger 30. Such actuators may interact with head 32 ofplunger 30 via a suitable link 42, which may be a mechanical link and/ora hydraulic link, for example. Suitable actuating systems 40 aredisclosed in U.S. Patent Application Publication Nos. 2011/0232606 and2013/0270369, for example, the disclosures of which are expresslyincorporated herein by reference in their entirety.

The second or lower end 14 of injector 10, which includes outletchannels 28 in injector body 20 and passageways 38 in plunger 30, isshown in more detail in FIG. 5. FIG. 5 corresponds to the openarrangement of FIG. 4, with passageways 38 being shown in fluidcommunication with outlet channels 28.

Each outlet channel 28 has an inlet end 50 and an outlet end 52, andeach passageway 38 has an inlet end 60 and an outlet end 62. Whenplunger 30 is in an open arrangement, as shown in FIG. 5, outlet end 62of passageway 38 is positioned in fluid communication with inlet end 50of the corresponding outlet channel 28. By contrast, when plunger 30 isin a closed arrangement, as shown in FIG. 1, plunger 30 interacts withinner wall 21 of injector body 20 to interrupt fluid communicationbetween outlet end 62 of passageway 38 and inlet end 50 of thecorresponding outlet channel 28.

The size, shape, and orientation of each outlet channel 28 andpassageway 38 may vary. With respect to outlet channel 28 of FIG. 5, forexample, the diameter D₁, the length L, and the channel angle α betweenchannel axis C and reference plane R may vary. The cross-sectional shapeof each outlet channel 28 may also vary. For example, outlet channel 28may be circular in cross-section, as shown in FIG. 6A, oval incross-section, as shown in FIG. 6B, and/or may include one or moreradial extensions 29, as shown in FIG. 6C. With respect to passageway 38of FIG. 5, for example, the diameter D₂ and the generally L-shapedpathway may vary. The number of outlet channels 28 and passageways 38may also vary. Outlet channels 28 and passageways 38 may be formed byabrasive flow machining (AFM), electric discharge machining (EDM), lasermachining, or other suitable manufacturing methods.

In the direction of longitudinal axis A of injector 10, each outletchannel 28 may have at least a first side 54 and a second side 56. Inthe illustrated embodiment of FIG. 5, first side 54 of outlet channel 28is the upper half or “high side” of outlet channel 28 that is locatedabove channel axis C, and second side 56 of outlet channel 28 is thelower half or “low side” of outlet channel 28 that is located belowchannel axis C. First side 54 and second side 56 of the illustrativeoutlet channel 28 are arranged in fluid communication with one another,such that fluid in first side 54 of outlet channel 28 may travel tosecond side 56 of outlet channel 28, and vice versa.

Outlet end 62 of each passageway 38 may be smaller in size (i.e.,narrower) than inlet end 50 of the corresponding outlet channel 28. Forexample, as shown in FIG. 5, diameter D₂ at outlet end 62 of passageway38 may be smaller than diameter D₁ at inlet end 50 of the correspondingoutlet channel 28. In this manner, outlet end 62 of passageway 38 may bemoved to a plurality of different open arrangements between first side54 and second side 56 of the corresponding outlet channel 28, as shownin FIGS. 2-4.

By moving plunger 30 between the plurality of different openarrangements shown in FIGS. 2-4, actuating system 40 may control theposition of each passageway 38 relative to each outlet channel 28. As aresult, actuating system 40 may also control the introduction of fluidinto inlet end 50 of each outlet channel 28 from outlet end 62 of eachpassageway 38, the velocity distribution of the fluid within eachindividual outlet channel 28, and the trajectory of the resulting fluidspray from outlet end 52 of each outlet channel 28. This trajectorycontrol method is described further below with reference to FIGS. 7-12.

A first spray trajectory or axis S₁ from outlet channel 28 is describedwith reference to FIG. 7 (which corresponds to the first openarrangement of FIG. 2). In this arrangement, fluid is introduced toinlet end 50 of outlet channel 28 at a first position P₁ correspondingto first side 54 (i.e., the “high side”) of outlet channel 28. Some ofthe fluid may travel to second side 56 (i.e., the “low side”) of outletchannel 28 before reaching outlet end 52. Upon reaching outlet end 52,the fluid in first side 54 of outlet channel 28 may be traveling fasterthan the fluid in second side 56 of outlet channel 28. In other words,the velocity distribution at outlet end 52 may be biased toward firstside 54 of outlet channel 28, which may be referred to herein as a“biased high” velocity distribution. A “biased high” velocitydistribution is shown schematically in FIG. 8. Upon exiting outlet end52, the “biased high” velocity distribution may cause the resultingfluid spray to travel downwardly relative to channel axis C along afirst spray axis S₁, as shown in FIG. 7. The first spray angle of thefirst spray axis S₁ may be deeper than the channel angle a of thechannel axis C relative to the reference plane R.

A second spray trajectory or axis S₂ from outlet channel 28 is describedwith reference to FIG. 9 (which corresponds to the second openarrangement of FIG. 3). In this arrangement, fluid is introduced toinlet end 50 of outlet channel 28 at a second position P₂ correspondingto second side 56 (i.e., the “low side”) of outlet channel 28. Some ofthe fluid may travel to first side 54 (i.e., the “high side”) of outletchannel 28 before reaching outlet end 52. Upon reaching outlet end 52,the fluid in second side 56 of outlet channel 28 may be traveling fasterthan the fluid in first side 54 of outlet channel 28. In other words,the velocity distribution at outlet end 52 may be biased toward secondside 56 of outlet channel 28, which may be referred to herein as a“biased low” velocity distribution. A “biased low” velocity distributionis shown schematically in FIG. 10. Upon exiting outlet end 52, the“biased low” velocity distribution may cause the resulting fluid sprayto travel upwardly relative to channel axis C along a second spray axisS₂, as shown in FIG. 9. The second spray angle γ of the second sprayaxis S₂ may be shallower than the channel angle a of the channel axis Crelative to the reference plane R.

A third spray trajectory or axis S₃ from outlet channel 28 is describedwith reference to FIG. 11 (which corresponds to the third openarrangement of FIG. 4). In this arrangement, fluid is introduced toinlet end 50 of outlet channel 28 at a third position P₃ correspondingto channel axis C between first side 54 and second side 56. The velocitydistribution at outlet end 52 may be substantially balanced betweenfirst side 54 and second side 56, which may be referred to herein as a“balanced” velocity distribution. A “balanced” velocity distribution isshown schematically in FIG. 12. Upon exiting outlet end 52, the“balanced” velocity distribution may cause the third spray axis S₃ togenerally follow channel axis C, as shown in FIG. 11. The third sprayangle δ of the third spray axis S₃ may be equal to the channel angle aof the channel axis C relative to the reference plane R.

In summary, by introducing fluid to each outlet channel 28 at a desiredposition P₁, P₂, P₃, the resulting fluid spray from each outlet channel28 may be delivered along a desired spray trajectory or axis S₁, S₂, S₃.It is also within the scope of the present disclosure to introduce fluidto each outlet channel 28 at a plurality of positions other than (e.g.,between) the above-described positions P₁, P₂, P₃ to produce additionalfluid spray trajectories. Although the illustrated fluid spraytrajectories S₁, S₂, S₃ are linear, the fluid spray trajectories S₁, S₂,S₃ may bend or curve in a non-linear manner.

Referring next to FIG. 13, a combustion system 1300 according to oneembodiment of the present disclosure is depicted as including theinjector 10 (not fully shown), a cylinder 1302, and a piston 1304.Cylinder 1302 generally includes a cylinder cavity 1306 and piston 1304.Cylinder 1302 is generally formed in an engine block (not shown). Acylinder head (not shown) is positioned on a top surface 1314 ofcylinder 1302. The bottom surface of the cylinder head attaches toengine block closing cylinder 1302 from its top surface 1314 and forminga combustion chamber 1308. Piston 1304 is slidably disposed within thecylinder 1302. It should be understood that while piston 1304 is shownin FIG. 13, in certain embodiments, piston 1304 may have different shapewithout affecting implementation of the present disclosure. The cylinderhead includes an exhaust passage (not shown), an intake passage (notshown) and an injector bore (not shown). Injector 10 is securely mountedinto the injector bore formed within the cylinder head for injectingfuel in combustion chamber 1308. The exhaust passage formed in thecylinder head directs exhaust gases from combustion chamber 1308 and anintake passage directs intake air into combustion chamber 1308.

The piston 1304 generally includes a depending cylindrical wall 1310, atop surface 1314, a piston crown 1312, and lower surface 1316. Topsurface of piston 1304 cooperates with the cylinder head and a portionof cylinder 1302 that extends between the cylinder head and piston 1304to define combustion chamber 1308. Although not specifically shown inFIG. 13, piston 1304 is connected to a crankshaft by way of a connectingrod which translates reciprocal movement of piston 1304 along arectilinear path within cylinder 1302 into rotational movement of thecrankshaft in a manner that is well known in the art.

Still referring to FIG. 13, an upper portion of piston 1304 is referredto as piston crown 1312. Injector 10 is slidably disposed within thecylinder 1302. Piston crown 1312 is configured to receive fuel frominjector 10. The desired spray trajectory S₁, S₂, S₃ (as shown) may bechosen to control the interaction between the fuel spray and the air inpiston crown 1312 of combustion chamber 1308. In operation, actuatingsystem 40 may be configured to move plunger 30 (FIG. 1) based on one ormore engine operating conditions (e.g., engine load, engine speed) totarget a certain feature or location of piston crown 1312 with thedesired spray trajectory S₁, S₂, S₃. Such targeting between the fuelspray and the air in combustion chamber 1308 may minimize emissions andimprove fuel economy.

Referring now to FIG. 14, an exhaust system 1400 according to oneembodiment of the present disclosure is depicted as including theinjector 10 (not fully shown), a particulate filter 1402, adecomposition reactor 1404, and a selective catalytic reduction (SCR)catalyst 1406. Decomposition reactor 1404 is connected downstream toparticulate filter 1402 and upstream to the SCR catalyst 1406. Thedecomposition reactor 1404 includes a diesel exhaust fluid (DEF) dosingvalve 1408 which is connected to a tank (not shown) containing DEF.Injector 10 is disposed into the DEF dosing valve 1408. Particulatefilter 1402 is connected to exhaust passage (not shown) via an exhaustline 1410.

Operationally, exhaust from the combustion chamber 1308 (FIG. 13) entersinto particulate filter 1402 over a diesel oxidation catalyst into awall-flow filter. Carbon particles are contained in the wall-flowfilter. Nitric oxide in exhaust is converted into nitrogen dioxide (NO₂)in the diesel oxidation catalyst. As nitrogen dioxide (NO₂) flowsthrough the wall-flow filter, it reacts with carbon (in wall-flowfilter) to produce carbon dioxide (CO₂) and nitrogen oxide (NO). As theexhaust passes into the decomposition reactor, injector 10 sprays asmall amount of DEF into hot exhaust stream 1404 forming ammonia (NH₃),through a series of reactions. Together nitrogen oxide (NO) and ammonia(NH₃) passes through SCR catalyst 1406 forming water vapor and nitrogen.As explained above with reference to FIG. 13, actuating system 40 may beconfigured to move plunger 30 (FIG. 1) based on one or more engineoperating conditions (e.g., engine load, engine speed) to target acertain feature or location in decomposition reactor 1404 with thedesired spray trajectory S₁, S₂, S₃. It should be understood that whilecombustion system 1300 and exhaust system 1400 are described hereinaboveas having the injector 10, in certain embodiments, injector 10 may bepositioned in other systems, for example, liquid hydrocarbon dosingsystems, without affecting implementation of the present disclosure.

While this invention has been described as having exemplary designs, thepresent invention can be further modified within the spirit and scope ofthis disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

What is claimed is:
 1. An injector, comprising: an injector bodycomprising: an inner wall that defines an injector cavity for fluid; atleast one inlet channel into the injector cavity; and at least oneoutlet channel from the injector cavity; a plunger that defines at leastone passageway between the injector cavity and the at least one outletchannel, the plunger being movable longitudinally in the injector cavitybetween at least: a first open arrangement in which the at least onepassageway is positioned to direct fluid into the at least one outletchannel at a first position; and a second open arrangement in which theat least one passageway is positioned to direct fluid into the at leastone outlet channel at a second position different from the firstposition.
 2. The injector of claim 1, wherein the first position isspaced longitudinally from the second position.
 3. The injector of claim1, wherein the at least one outlet channel has an inlet end, an outletend, and a channel axis between the inlet end and the outlet end, andwherein the first position is located on a first side of the channelaxis and the second position is located on a second side of the channelaxis.
 4. The injector of claim 1, wherein the plunger is further movableto a closed arrangement in which the at least one passageway isprevented from directing fluid into the at least one outlet channel. 5.The injector of claim 4, wherein the inner wall of the injector bodyblocks the at least one passageway when the plunger is moved to theclosed arrangement.
 6. The injector of claim 1, wherein the plunger isfurther movable to a third open arrangement in which the at least onepassageway is positioned to direct fluid into the at least one outletchannel at a third position located longitudinally between the first andsecond positions.
 7. The injector of claim 1, wherein the at least onepassageway is narrower than the at least one outlet channel.
 8. Amethod, comprising: positioning a plunger in a first open arrangement ina body having an outlet channel; directing fluid through the plunger inthe first open arrangement and into a first side of the outlet channelto produce a first spray trajectory from the outlet channel; moving theplunger to a second open arrangement; and directing fluid through theplunger in the second open arrangement and into a second side of theoutlet channel to produce a second spray trajectory from the outletchannel different from the first spray trajectory.
 9. The method ofclaim 8, wherein: with the plunger in the first open arrangement, thefluid has a first velocity distribution in the outlet channel; and withthe plunger in the second open arrangement, the fluid has a secondvelocity distribution in the outlet channel different from the firstvelocity distribution.
 10. The method of claim 9, wherein the firstvelocity distribution is biased toward the first side of the outletchannel and the second velocity distribution is biased toward the secondside of the outlet channel.
 11. The method of claim 8, wherein theoutlet channel has a channel axis, the first spray trajectory having afirst spray angle relative to a reference plane that is deeper than anangle between the channel axis and the reference plane, and the secondspray trajectory having a second spray angle that is shallower than thechannel axis.
 12. The method of claim 8, wherein the moving step isperformed based on at least one engine operating condition.
 13. Themethod of claim 8, further comprising: moving the plunger to a thirdopen arrangement; and directing fluid through the plunger in the thirdopen arrangement and into the outlet channel to produce a third spraytrajectory from the outlet channel; wherein moving the plunger to thethird open arrangement is performed based on at least one engineoperating condition.
 14. The method in claim 13, wherein with theplunger in the third open arrangement, the fluid has a third velocitydistribution in the outlet channel.
 15. The method in claim 14, whereinthe third velocity distribution is balanced between the first side andthe second side of the outlet channel.
 16. The method of claim 13,wherein the third spray trajectory has a third spray angle that followsthe channel axis.
 17. A combustion system, comprising: a combustionchamber; a piston disposed in the combustion chamber; and an injectorhaving an injector body, the injector body comprising an inner wall thatdefines an injector cavity, at least one inlet channel into the injectorcavity, and at least one outlet channel from the injector cavity, aplunger that defines at least one passageway between the injector cavityand the at least one outlet channel, the plunger being movable in theinjector cavity between at least: a first open arrangement in which theat least one passageway is positioned to direct fluid into the at leastone outlet channel at a first position, and a second open arrangement inwhich the at least one passageway is positioned to direct fluid into theat least one outlet channel at a second position different from thefirst position.
 18. The combustion system of claim 17, wherein the firstposition is spaced longitudinally relative to a direction of movement ofthe plunger from the second position.
 19. The combustion system of claim17, wherein the at least one outlet channel has an inlet end, an outletend, and a channel axis between the inlet end and the outlet end, andwherein the first position is located on a first side of the channelaxis and the second position is located on a second side of the channelaxis.
 20. The combustion system of claim 17, wherein the at least onepassageway is narrower than the at least one outlet channel.
 21. Anexhaust system, comprising: a particulate filter; a decompositionreactor downstream of the particulate filter; a selective catalyticreduction system downstream of the decomposition reactor; and aninjector having an injector body, the injector body comprising, an innerwall that defines an injector cavity, at least one inlet channel intothe injector cavity and at least one outlet channel from the injectorcavity, a plunger that defines at least one passageway between theinjector cavity and the at least one outlet channel, the plunger beingmovable in the injector cavity between at least: a first openarrangement in which the at least one passageway is positioned to directfluid into the at least one outlet channel at a first position, and asecond open arrangement in which the at least one passageway ispositioned to direct fluid into the at least one outlet channel at asecond position different from the first position; wherein the injectoris disposed in the decomposition reactor.
 22. The exhaust system ofclaim 21, wherein the first position is spaced longitudinally relativeto a direction of movement of the plunger from the second position. 23.The exhaust system of claim 21, wherein the at least one outlet channelhas an inlet end, an outlet end, and a channel axis between the inletend and the outlet end, and wherein the first position is located on afirst side of the channel axis and the second position is located on asecond side of the channel axis.
 24. The exhaust system of claim 21,wherein the at least one passageway is narrower than the at least oneoutlet channel.